Lubricating composition



Patented June 6 1939 UNITED STATES 2,161,560 LUBRICATING COMPOSITIONMoses L. Crossley, -Plainl'leld, N. J., assignor to Calco Chemical Co.Inc., Bound Brook, N. J., a corporation of Delaware No Drawing.

Application December '24, 1936,

Serial No. 117,586

2 Claims.

This invention relates to lubricating compositions and particularly tothe so-called extreme pressure lubricants.

The standard lubricants for heavy duty service, 5 that is, in internalcombustion engines, are mostly hydrocarbon oils. These mineral oils whenproperly refined are very stable under heat but they are deficient inoiliness and in the strength of the oil film which is formed betweenmetal surfaces takes place. Both factors of film strength and oilinessare of great importance in the lubrication of heavy duty bearings suchas are encountered in modern internal'combustion engines or in geartransmissions with high tooth pressures, for example hypoid gears;Insufiicient film strength will result in metal to metal contact evenwhen an adequate quantity of lubricant is supplied to the bearing andinsufiicient oiliness will prevent retention of an Oil film in thebearing when for any reason a lubricant supply becomes insuflicient.Both deficient oiliness and deficient film strength permit metal tometal contact which results in higher wear and also in the rapiddevelopment of heat. Modern high speed internal combustion enginesoperate at so close to the limit of bearing pressures and rubbing speedsthat it has been necessary to change the material used in the bearing,for example, to substituted certain bearing metals such as alloyscontaining silver, cadmium and the like, for' the standard Babbittmetals. 4

Film strength and oiliness are probably due to molecular forces in theoil film, the molecules of which have the property of wetting oradhering to the metal surface. An oil filin is retained tenaciously evenwhen the lubricant supply is interrupted for considerable periods oftime.

In the'past, the problem was first attacked by the incorporation ofsmall amounts of fatty acids into the oil. These compounds did in 'factincrease the oiliness to some extent probably due to soap formation ofthe free acid with the metal of the bearing surface, but they did notproduce films of high strength and corrosion and other difficultiesrendered their use undesirable. Certain esters suchas tricresyl andtriphenylphosphate and chlorinated esters .of fatty acids with mono ordihydric alcohols have been proposed and have achieved some commercialsuccess, notably in the case of tricresylphosphate and chlorinatedstearic acid esters. The presence of the acid radical even thoughcombined in ester form was therefore considered to be a necessarycharacteristic of the compounds.

in bearings or at other points where lubrication According to thepresent invention, I have found that certain halogenated compoundswhichare neither esters, acids or derivatives, possess the property ofincreasing film strength to an extraordinary degree and also improvingthe oiliness. These compounds are halogenated poly nuclear phenols,particularly chlorinated naphthols. The products are relatively cheap,are neutral and do not present corrosion problems and a small additionon the order of 1% produces an extraordinary increase in film strengthand a notable increase in oiliness, the film strength increase beingmarkedly better than ester compounds such as tricresylphosphate.

The present invention is not limited to any particular quantity of addedchlorinated polynuclear phenol. In general, from about V2 to 1% of thelubricating oil gives satisfactory results. Smaller amounts tend tolower'film strength and oiliness and much larger amounts do not bringabout an increase in film strength and oiliness sufllcient to compensatefor the additional cost.

While the invention is not limited to any particular halogenatedpolynuclear phenol, the chicrinated betanaphthol compounds give bestresults, although the alphanaphthols, anthranols, hydroxyphenanthrenesand the like show similar properties and can be used eii'ectively.

Example 1 A standard mineral lubricating oil was admixed with 375%alphachlorbetanaphthol. When tested on the standard lubricant tester ofthe Bureau of Standards with a high speed test specimen at 2500 R. P. M.and low speed test specimen at 417 R. P. M. giving a speed ratio of 6:1under 12.1 lbs. per second rate of loading and F. oil temperature, theload carrying capacity was 345 lbs. as compared to 148 lbs. for themineral 011 without addition.

Example 2 p 37% of polychlorbeta'. naphthol containing about 4 chlorineatoms was mixed with the same mineral oil as in Example 1 and testedunder the. same conditions by the Bureau of Standards. A load carryingcapacity of 1125 lbs. was registered on the machine.

The above figures may be compared with a commercial product soldextensively on the market and using 1% of tricresylphosphate. Thiscomposition, which employed the same mineral oil when tested on themachine showed a 'load carrying capacity of lbs. as against 148 for theoil without any tricresylphosphate. It will be apparent that even thelowest chlorinated naphthol of the present invention increased the loadcarrying capacity of the film by more than 100% as against an increaseof between 8 and 9% fortricresylphosphate and the most eifective type ofproduct of the present invention, namely polychlorbetanaphthol,increased the load carrying capacity nearly 800%.

Example 3 One percent of chloralphanaphthol was blended with a standardmineral oil and tested in an Amsler machine. The torque was 63 ft. lbs.under a load of 300 kilograms. This compares with a torque of 68 ft.lbs. for one percent tricresylphosphate solution with 160 lbs. load. In

other words, chloralphanaphthol requires less torque under almost doublethe load.

eral lubricating oil and a small amount of polychlorinated naphthol.

2. A lubricating composition comprising a mineral lubricating oil and asmall amount of polychlorinated betanaphthol.

MOSES L. CROSSLEY.

